1. Field of the Invention
The present invention relates to cultivators for row crops, and in particular to means for mounting rolling disk shields on the cultivator.
2. Description of the Prior Art
Prior art cultivators for row crops, such as corn and soy beans, often employ a pair of rotary, row-defining disks mounted on a common shaft attached to a transverse tool bar which supports the entire cultivator assembly. The purpose of these disks is to prevent the dirt which is thrown up by the cultivator plow elements from covering the young plants, and for this reason, they are normally positioned such that they follow parallel paths on either side of and in fairly close proximity to the row.
One such prior art disk shield assembly is shown in U.S. Pat. No. 3,502,157 and comprises a pair of laterally spaced-apart coaxial disks rotatably mounted on a pivoted support arm which extends between them. The pivoted arm is supported by a second arm which is rigidly clamped to the tool bar. The primary drawback to this arrangement is that plants which are taller than 9 or 10 inches are knocked down or damaged by the pivoted arm which supports the disks. Furthermore, the entire disk assembly is supported directly by the rigid tool bar and the free end of the pivot arm is suspended from the bar by means of a chain which limits the level to which the disks can drop. Although the plow elements on many prior art cultivators are connected to the tool bar through a linkage which minimizes the effect of tool bar movement during operation, if the suspension chains of the above-described prior disk shield assembly are taut, the disks may be raised off the ground upon upward tool bar movement or when a depression or gully in the ground is encountered.